fix: test is sync and send

src/client.rs

@@ -1153,6 +1153,28 @@ mod test {
             .is_err());
     }
 
+    fn is_send<T: Send>(_send: T) {}
+
+    fn is_sync<T: Sync>(_sync: T) {}
+
+    #[test]
+    fn test_should_be_sync() {
+        let client = FtpFs::new("127.0.0.1", 10021)
+            .username("test")
+            .password("test");
+
+        is_sync(client);
+    }
+
+    #[test]
+    fn test_should_be_send() {
+        let client = FtpFs::new("127.0.0.1", 10021)
+            .username("test")
+            .password("test");
+
+        is_send(client);
+    }
+
     // -- test utils
 
     #[cfg(feature = "with-containers")]